Depression, neuropathology, and cognitive decline are commonly observed with repetitive head injuries (RHIs). We examined whether in boxers (a) clinically significant depression is associated with structural brain changes and cognition; (b) minimal symptoms of depression moderate the relations among RHI and brain volumes and cognition; and (c) baseline depression is associated with longitudinal cognitive changes.
Clinical Research Center.
A total of 205 male professional boxers.
Cross-sectional and longitudinal (subsample: n = 45; first visit to follow-up range = 1-6 years; mean = 2.61 years).
Patient Health Questionnaire-9 depression; CNS Vital Signs cognitive battery; brain imaging.
Clinically significant depression was associated with smaller regional volumes in insula, cingulate, orbitofrontal cortex, thalami, and middle corpus-callosum subregions; and with poorer verbal memory and psychomotor speed performance. Depression symptoms moderated the relations between RHI and bilateral thalami, left hippocampus, left medial orbitofrontal cortex, and bilateral insula volumes; but not cognition. Baseline depression was associated with poorer psychomotor speed and reaction time longitudinally and improved verbal memory performance longitudinally.
Clinical depression is associated with volumetric and cognitive changes occasioning RHI exposure, and even minimal depressive symptoms may moderate the relations between exposure and brain volumes in key regions. Longitudinally, there is preliminary evidence that depression precedes cognitive changes.
University of Nevada, Las Vegas (Mr Lee); Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, Nevada (Drs Bennett and Bernick and Mr Lee); Department of Environmental and Occupational Health, School of Community Health Sciences, University of Nevada, Las Vegas (Dr Shan); and Multidisciplinary Memory Clinic, Department of Neurosciences, University of California San Diego, La Jolla (Dr Banks).
Corresponding Author: Sarah J. Banks, PhD, Multidisciplinary Memory Clinic, Department of Neurosciences, University of California San Diego, 9500 Gilman Dr, La Jolla, CA 92093 (firstname.lastname@example.org).
Funding for this study came from Belator, UFC, the August Rapone Family Foundation, Top Rank, Haymon Boxing, and an Institutional Development Award from the National Institute of General Medical Sciences of the National Institutes of Health under grant number P20GM109025.
Mr Lee, Dr Bennett, Dr Bernick, and Dr Banks received research funding to complete this research and Dr Bernick receives speaking fees tied to his ongoing work. Funds for this project are not contingent upon the findings of this study and go toward research costs and salaries. Speaking engagements by Dr Bernick are paid engagements not directly related to this article.
The authors declare no conflict of interest.